1. Field of the Invention
The present invention relates to an X-ray diagnosis apparatus.
2. Description of the Related Art
Recently, an X-ray diagnosis apparatus is used during a treatment as well as during an examination. For example, according to a coil embolization that is an intervention treatment for a head aneurysm, a filling state of a coil is an important factor that leads to a successful treatment. For this reason, to begin with, during an examination, an operator of the X-ray diagnosis apparatus carries out rotational imaging of a head of a subject by using the X-ray diagnosis apparatus, thereby specifying the shape and the position of an aneurysm from acquired three-dimensional blood-vessel image data. During a treatment, the operator then performs imaging while changing an imaging angle, or performs imaging from several directions by using an X-ray diagnosis apparatus of a bi plane type, and confirms a filling state of a coil from taken X-ray images.
However, because an aneurysm is small, usually 10 millimeters or smaller, an operator often performs imaging by enlarging a field of view of the imaging during a treatment; if the imaging angle is changed, a region of interest of the subject may be sometimes dislocated from the field of view (dislocated from an effective image reception area of a detector) in some cases. In such case, to find the region of interest, the operator reduces the scale of image enlargement at first so as to observe a wider region, and while observing a radioscopic image by further radiating X-rays onto the subject, the operator adjusts imaging positions (for example, the angle of a supporting device, the position of the supporting device, the position of a couch, and the height of the couch), and arranges the region of interest to the center of the field of view so as to observe the region of interest easily. After that, to observe the region of interest easily, the operator again performs a fine adjustment of the scale of image enlargement and the imaging positions while observing a radioscopic image by radiating X-rays onto the subject. Moreover, when using the X-ray diagnosis apparatus of the bi plane type during a treatment, the operator needs to position the region of interest of the subject at the center of the field of view by repeating the same procedure as described above as an initial setting, and to perform a fine adjustment to make the scale of image enlargement and the imaging positions more suitable for the treatment.
For this reason, conventionally a technology has been disclosed that the operator specifies the position of a region of interest by imaging the subject from a plurality of directions such that the specified position comes to the center of rotation of a C-arm of the X-ray diagnosis apparatus. A technology of specifying the position of a region of interest on a three-dimensional image is also disclosed (for example, JP-A 2001-204718 (KOKAI), and JP-A 2002-136507 (KOKAI)).
However, the conventional technologies described above have a problem that operation efficiency is decreased. Precisely, according to JP-A 2001-204718 (KOKAI), the position of a region of interest needs to be specified by performing imaging from at least two directions; and according to JP-A 2002-136507 (KOKAI), the position of a region of interest needs to be specified on a three-dimensional image. However, such specifying operations are not included in a clinical work flow, consequently produce additional time and effort onto the operator, and reduce operation efficiency. In addition, only specifying a region of interest to come to the center of a field of view is not enough to carry out a treatment, and a fine adjustment of the scale of image enlargement and imaging positions need to be further performed while confirming a radioscopic image by radiating X-rays onto the subject, still there is radiation exposure during the fine adjustment that is irrelevant to the essence of the treatment.